Treatment of livers



Patented May 24, 1949 srArEs i; TREATMENT OF LIVERS Levi:

Swift 1 & Gompany, -or Illinois ScottTaddock, Chicago, Ill., assignortto Chicago, 111., a corporation him-Drawing. l Application June 16, 1945, .=Serial No. 599,958

"3 Claims.

.This j. invention relates i to .the 1. treatment 1 of m a Products... and it. has. to .ido .more particularly with a method of. conditioning a liver product ..Witl1,,a, proteblytic enzyme for the subsequent tenderizing thereof. on cookin i1Liver .is an important edible iproduct of'the meat. pa'ckingindustry. because-of. its nutritional value. ilnltheilast ,iew, years the importance of live inlt ehumandiet' has been recognized, .especially'in view.of.ftl'leZdiscovery.ofv its high vita- .minscontent. and its curative properties in the treatment. of. anemia, a .bloodjdeficiency disease.

.Unlikeany other organpf the animal body, the '1iver,..with1 the. exception of the lungs, has a peculiar yascular..sy'stem, the ,blood vessels being large. and thick-walled. .Theseblood vessels, entering the liver organatacleft, via .the portal fissureiound attthe'rtop center of the organ,'divide and branch 'throughout'the mass of the liver substance. Because bran abundance of blood vessel tissue in the liver, especially near the portal uissure, certain portions of the liver are hard and rubbery upon mastification when the chew includes a portion of" a-iblood' yessel.

It is the object of this invention, therefore, to

pre-treat the liver to enable tenderization of theblood vessels that cause the hardness on chewing by means -ofa proteolytic enzyme, such as' bromelin; trypsirr orpapain,-at the same time preventing theeengyme from. escapin into the levertissue which is already sufficiently tender.

.It has been known heretofore, that meat .products could ,be quick cured byLintroducingalcuringagent intothe vascular system. However,

the introduction of an enzyme solution by means .1

of pumping as in quick curing causes a bursting or puncturation of the blood vessels and the consequent escape of the enzyme solution into the meat tissue of the liver, thus effecting an overtenderization thereof.

The present invention provides a practical method for the introduction of the enzyme which on cooking of the liver tenderizes the blood vessel tissue and leaves the remainder of the liver substance unaffected. Broadly the invention contemplates subjecting the liver to the action of the enzyme solution while under vacuum whereby the solution contacts the vascular tissue without substantially affecting the meat tissue.

One method of practicing the invention is to ,2 charge the liver product and the-enzyme. solution to a vacuumized container. The container may be equipped with a vacuumgauge, an evacuating pump, .and. othernecessary equipment. for. releasing the vacuulnand ior..providing..accessto the container.

.Good resultsare obtained if the concentration of the enzyme Ia1ls.,within-..the. range o.f..0.01. to 0.1 percent. Optimum results...are..manifested at .a concentration oflapproximately 07.04. .to..0..08 percent of. the enzyme.

To the enzyme solution may be added. curing materials, such. assalt, sodium.. nitrate andrsodium nitrite. Salt. alone..may..-be. included in the bath solution .if .no particular. colorspropertiesof .thefinalproduct aresought. cBy the incorporation of .5 to 25-. per. cent.of...salt.in the bath solution, substantial curing may be ..0btained ...In addition to the curing function, the .saltuoften stimulates .the activity. 'of. the enzyme.

.As vacuumlis. applied. tolthe... system, Lthe. air leaving the .liverbirbhlee up throughithe. solution at a rapid rate, while atthe same ltimefthe large blood vessels open .up .and'. become .distended. During the evacuating.processsandionrelease .of the vacuum, some.enzymel trickles .intothe .distended blood vessels. A vacuum. of .between 20 to 30 inches may housed. iGood .results..are (obtained at a vacuum'oj25..to.zflinchesofmercury. .The vacuum ..is. maintainedimr about 1 10 to. .30 minutes and. then released.

vConvenientlythe. enzyme is .usediat roomtem- .perature, although the temperature range of the .solution may vary Within wideilimitsiorexample, between-401w- 115?.F. 1 However, after the liver product is withdrawnlfrom'the vessel. and the surface thereof washed'free of enzyme by means of water, if not used immediately, the liver product should be refrigerated in order to arrest any enzyme activity affecting the strength of the blood vessels, and to maintain the enzyme associated with the blood vessels in a dormant state until such time as the liver product is to be cooked. During the cooking the enzyme within the blood vessels is reactivated by the heat in the cooking process, and it is at this time that a substantial tenderization of the blood vessels occurs. Refrigeration temperatures depend on the length of storage. Temperatures of approximately 36 to 38 F. may be employed where a short period of storage is contemplated. If the storage time is to exceed 7 to days, it is preferred that the liver product be frozen.

The following examples of methods of operatin are given for the purpose of illustrating the present invention, but they are not intended to be limiting on the scope thereof.

Example I Example II A fresh cow liver weighing approximately 9 pounds is immersed in an enzyme salt bath con posed of 0.08 per cent papain, 10 per cent salt, and the remainder, water. The level of the solution is kept l to 2 inches above the surface of the liver. A vacuum of 25 to 27 inches of mercury is obtained and is kept for 10 minutes after which it is released and the treated liver withdrawn.

Example III An enzyme salt solution comprising 0.08 per cent papain, 10 per cent salt and 0.1 sodium n nitrite is placed in a vacuum jar and a chilled liver weighing 9% pounds is immersed therein. A vacuum of 25 to 27 inches of mercury is then obtained and held for minutes, after which it is released, and the liver product withdrawn and the surface thereof washed free of enzyme solution.

Obviously many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope if liver, and thereafter maintaining the said enzyme thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. A process for conditioning the blood vessels of an animal liver with a proteolytic enzyme for the tenderization thereof without afiecting the meat tissue of the liver which comprises essentially the steps of immersing an animal liver characterized by having an outer layer of connective tissue and a network of tough, thick-walled blood vessels in a solution of a proteolytic enzyme in a confined zone, subjecting the immersed liver to a vacuum of between approximately to inches of mercury to open and distend the blood vessels, and releasing the said vacuum so as to allow the proteolytic enzyme solution to enter the distended blood vessels without rupture of said vessels, whereby the enzyme becomes associated with the tough blood vessels without contacting the said meat tissue of the liver.

2. A process for conditioning the blood vessels of an animal liver with a proteolytic enzyme for the tenderization thereof without afiecting the meat tissue of the liver which .comprises essentially the steps of immersing an animal liver characterized by having an outer layer of connective tissue and a network of tough, thickwalled blood vessels in a solution of a proteolytic anzyme in a confined zone, said enzyme solution having a concentration between approximately 0.01 and 0.1 per cent, subjecting the immersed liver to a vacuum of between approximately 20 to 30 inches of mercury for a period of between 10 to 30 minutes to open and distend the blood vessels, and releasing the said vacuum so as to allow the proteolytic enzyme solution to enter the distended blood vessels without rupture of said vessels, whereby the enzyme becomes associated with the tough blood vessels without contacting the said meat tissue of the liver.

3. A proces for conditioning the blood vessels of an animal liver with a proteolytic enzyme for the subsequent tenderization thereof on cooking without affecting the meat tissue of the liver which comprises essentially the steps of immersing an animal liver characterized by having an outer layer of connective tissue and a network of tough, thick-Walled blood vessels in a solution of a proteolytic enzyme in a confined zone, said enzyme solution having a concentration between approximately 0.01 and 0.1 per cent, subjecting the immersed liver to a vacuum of between ap proximately 20 to 30 inches of mercury for a period of between 10 to 30 minutes to open and distend the blood vessels, releasing the said vacuum so as toallow the proteolytic enzyme solution to enter the distended blood vessels without rupture of said vessels, whereby the enzyme becomes associated with the tough blood vessels without contacting the said meat tissue of the in a dormant state until the liver is cooked to tenderize the said blood vessels.

LEVI SCOTT PADDOCK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Nmnber Name Date 4,035 Scherpf May 7, 1845 1,936,074 Tressler et al Nov. 21, 1933 2,140,781 Allen Dec. 20, 1938 FOREIGN PATENTS Number Country Date 166,927 Great Britain July 20, 1921 413,183 Great Britain July 12, 1934 

